question

4senergy avatar image
4senergy asked

Why the VRM is giving wrong information?


—> I have 4 Quattro 10 kVA configured for split phase (240 V)

—> 3 SMA sunny boys SB7.7

—> 3 Lithium ion phosphate battery. 14.4 kWh each.

—> 40 kVA split phase Diesel Generator.

The sunny boys and the Cerbo GX are connected in the same local network. With some configuration in the sun boys ( Enable TCP, Modbus Server, and different address for each inverter), the Cerbo can now read information from the solar inverters ( picture showing device list). As you can see in the picture the VRM says that

1- the Load is 0 which is not true. I understand that this reading is because the load is satisfied by the PV production and excess power goes to battery. But if the Cerbo can read the amount of power being produced by the sunny boys it should do the math.

Load = PV power - battery charging power

Load = PV power + battery discharging power

2- The same amount of PV production is shown in the Generator side but with negative value as if excess power is being exported, which is not true cause input breakers are off and generator is not running.

cerbo gxVRMmonitoring
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2 Answers
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·

Hi @4SEnergy,

This occurs when the AC PV location is set to AC input, instead of AC output.

You can change the location of the AC PV in the device menu of the GX.

On your GX, go to settings -> PV inverters. There you can see all detected PV inverters.

You can set the position for each of the PV inverters, if it is on AC-In or AC-Out.

cleanshot-2023-10-28-at-073315.jpg

Don't forget to configure the PV-inverters on AC-Out inside the ESS Assistant.


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4senergy avatar image
4senergy answered ·

Thank you Guy Stewart for your answer!!!

I used the PV support assistant to define the sunny boy frequency shift power control settings. I don’t use the ESS assistant. Should I use it instead.

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Guy Stewart (Victron Community Manager) avatar image Guy Stewart (Victron Community Manager) ♦♦ commented ·
No, only if it’s an ESS system. Just a reminder that is another spot where this kind of issue could manifest.


PV inverter assistant location, plus GX PV inverter location is enough.

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